Answer:
Yesterday I squeezed 2 kilos of apples in a barrel.
Today I have picked 5 extra kilos of apples and save them in a basket.
By the end of the day, I want to squeeze some of them and add to the barrel.
Apple juice from the barrel is valued 3 times the same amount of raw apples.
I want to find how many apples I can squeeze today (x) such that the value of the remaining raw apples is equivalent to the total value of produced apple juice.
Explanation:
The equation is 5-x = 3 * (x + 2).
If x is the amount of apple to squeeze (in kilos) then 5-x is the remaining raw apples and x+2 is the total quantity of juice.
Since that juice is valued 3 times the raw apples we obtain the equivalence defined in the equation above.